Headset expander thingy - Diamondback Serios

Triathlon Forum
1

Well, my comeback is being held up by a corrosion problem. The original headset expander thingy that goes in the top of the steerer tube on my Serios got corroded enough that I can’t clamp the proprietary stem without a little bit of slop at the fork/frame interface. I need a new one but I don’t know the name of the part. It’s:

  • 1-1/8 steerer tube
  • the expander I have uses a bolt with a 6mm Allen head to expand the plug
  • a 5mm Allen bolt screws into the 6mm bolt head to pull the stem down onto the top of the fork

Do all expander woirk this way with 2 bolts, or is this special this kind of proprietary stem? What should I buy?

(Ok this got ramble-y but do you see my problem?)

Thanks,
Bigshoes

2

Good morning. The Serios looks like a nice bike, and from the different pictures I’ve seen of the small parts, the expander plug looks ordinary. The translation is that it does not appear to be proprietary like the stem so any standard plug such as a FSA will do the trick. I personally like Wolftooth’s offering but unsure it would work with that stem.

To be sure I found your bike, I’m posting the link here so that you can confirm.

Serios frameset with expander plug (third picture): Diamondback Serios BIH 58cm Carbon 700c Tri TT Bike Frame Fork New Old – Random Bike Parts

3

Oh perfect. That’s exactly it. I’ll go get myself some parts. Thank you!